c# aes AES/ECB/PKCS5Padding securerandom

C# 中的 AES (Advanced Encryption Standard) 是一种对称加密算法，常用于数据的安全传输。AES/ECB/PKCS5Padding 模式表示 Electronic Codebook (电子密码本) 模式，这是一种基本的块加密模式，将明文分成固定大小的数据块，每个块独立进行加密。PKCS5Padding 则是 Padding Scheme for Privacy-Preserving Cryptosystems (公钥加密系统隐私保护填充方案) 的简称，它添加一些额外的位以保证输入长度为块大小的整数倍。

SecurRandom 是 .NET Framework 提供的一个安全随机数生成器，它用于生成加密密钥、初始化向量（IV）等随机数据，确保加密过程的随机性和不可预测性。

使用示例：

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

public static class AesExample
{
    public static byte[] Encrypt(string plainText, string key, byte[] iv)
    {
        using (Aes aes = Aes.Create())
        {
            aes.Key = Encoding.UTF8.GetBytes(key);
            aes.IV = iv;

            ICryptoTransform encryptor = aes.CreateEncryptor(aes.Key, aes.IV, PaddingMode.PKCS7);

            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter sw = new StreamWriter(cs))
                    {
                        sw.Write(plainText);
                    }

                    return ms.ToArray();
                }
            }
        }
    }

    public static string Decrypt(byte[] cipherText, string key, byte[] iv)
    {
        byte[] decryptedBytes = null;
        try
        {
            using (Aes aes = Aes.Create())
            {
                aes.Key = Encoding.UTF8.GetBytes(key);
                aes.IV = iv;

                ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV, PaddingMode.PKCS7);

                using (MemoryStream ms = new MemoryStream(cipherText))
                {
                    using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader sr = new StreamReader(cs))
                        {
                            decryptedBytes = Encoding.UTF8.GetBytes(sr.ReadToEnd());
                        }
                    }
                }
            }
        }
        catch { /* Handle decryption errors */ }

        return Encoding.UTF8.GetString(decryptedBytes);
    }

    public static void Main()
    {
        // Generate a secure random IV
        byte[] iv = new SecureRandom().GetBytes(Aes.BlockSize);
        string key = "YourSecretKey"; // Replace with your own 16, 24, or 32-byte key

        // Encrypt some text
        string plaintext = "Hello, world!";
        byte[] encrypted = Encrypt(plaintext, key, iv);

        // Decrypt the data back to text
        string decrypted = Decrypt(encrypted, key, iv);
        Console.WriteLine($"Original: {plaintext}");
        Console.WriteLine($"Encrypted: {BitConverter.ToString(encrypted)}");
        Console.WriteLine($"Decrypted: {decrypted}");
    }
}